Closing unit for the nozzle strip on a nozzle beam for hydrodynamically needling fibres of a web of fabric

ABSTRACT

During the construction of the nozzle beam according to DE-A-195 01 738, the insertion slit for the nozzle strip ( 14 ) is sealed on the front side of the nozzle beam by means of a screwed cover ( 16,17 ). It is easier to exchange a nozzle strip ( 14 ) if a special closing unit ( 26 ) having an opening ( 3 ) for the nozzle strip is provided on the front side, and said opening ( 30 ) is closed in a liquid-tight manner by a simply fixed insertion mandrel ( 31 ).

The invention relates to a jet manifold on a device for generatingextremely fine fluid jets used in the hydrodynamic jet impingement offibers of a web moving along the manifold, such as a fiber web, tissue,etc., or a woven or knit, which manifold is composed of an upper sectionextending over the working length of the web, and of a lower section,wherein

a. a pressure chamber of round cross-section is located along the lengthof the upper section, the fluid being supplied under pressure, forexample, to the front side of the chamber;

b. a pressure distribution chamber is provided in the lower section inparallel to the above;

c. the pressure distribution chamber discharges into a narrow fluidoutlet slit opposite the cross-section of the pressure distributionchamber;

d. a jet strip is mounted in a fluid-tight fashion within the jetmanifold above the fluid outlet slit; and

e. this jet strip may be replaced through a closable opening on thefront side of the jet manifold.

A device of this type is disclosed in German Patent 195 01 738, thecontent plus drawings of which are referenced here as prior art. Withinthe pressure chamber, water pressures of up to 1,000 bar are generatedwhich, of course, act on the end walls of the jet manifold. In order toproduce the orifices in the manifold, the one front side must initiallybe open, then closed by covers. Special covers are provided for thepressure chamber as well as the pressure distribution chamber, thecovers being attached by screws to the jet manifold wall. A specialcover is also provided to close the jet strip replacement opening, thiscover also being attached to the jet manifold wall by screws. O-ringsrecessed in the sealing walls serve to provide a fluid-tight seal.

When replacement of the jet strip is required, the two screws located init which attach the cover to the manifold are loosened with ascrewdriver—after having shut off the water supply—and the cover andscrews set aside for reuse. Although only two screws need to beloosened, a screwdriver is still required for this operation, aprocedure which may be viewed as disadvantageous.

The goal of the invention is to find a solution for a jet manifold ofthe type referred to at the outset which allows for the rapidreplacement of the jet strip without equipment disassembly and without ascrewdriver.

The goal is achieved by

f) providing a closing unit on the closable opening which

g) is provided at the level of the jet strip mounting position with aninsertion slot for the jet strip, which slot

h) is closable by an insertion mandrel.

The insertion mandrel may be retained by a bolt secured within theclosing unit, which bolt may be easily removed from a hole retaining theinsertion mandrel in the jet manifold after shutting off the watersupply and thus the water pressure. Loss of the bolt may be prevented bysecuring it to the jet manifold using, for example, a thread-like link;the insertion mandrel may be removed by hand from the closing unit,preferably along with the jet strip, and the same items may then beinserted along with the insertion mandrel after replacement with a newstrip.

An example of a jet manifold of the type enhanced according to theinvention is shown in the drawings:

FIG. 1 shows a section through a conventional jet manifold;

FIG. 2 is a view of the front side of the jet manifold in FIG. 1;

FIG. 3 shows a section along line C—C in FIG. 1 providing a view of thelower section of the jet manifold;

FIG. 4 is a section along line IV—IV in FIG. 5, specifically, one of thetwo front sides of the jet manifold in FIG. 1 now enhanced by a newrapid replacement device for the jet strip;

FIG. 5 is a top view of the device in the region of the front side ofthe jet manifold;

FIG. 6 is a section through the closing unit, similar to that of FIG. 4with another retainer for the jet strip;

FIG. 7 is a section of the same type as in FIG. 6 with the insertionmandrel removed;

FIG. 8 is a top view of the device according to FIG. 6, and

FIG. 9 is a schematic diagram showing the procedure for rapidlyattaching the jet strip in the rapid replacement device of FIG. 6.

The jet manifold seen in FIGS. 1-3 is disclosed in German Patent 195 01738, but may be replaced by another item working on a similar principle.The housing of the jet manifold is composed of an upper section 1 whichis attached to the lower section 2 at multiple sites over its lengthfrom below by screws, not shown. Upper section 1 has two longitudinalcavities 4 and 5, of which the upper one is the pressure chamber 4 andthe lower one is the pressure distribution chamber 5. Both chambers areopen at the one front side but are closed by screw-attached covers 6 and7 forming a liquid-tight seal. At the other end, pressure chamber 4 hasan opening 4′ through which liquid is introduced under pressure. The twochambers 4 and 5 are separated by a partition 8. A large number ofpassages 9 in partition 8 over the length of the jet manifold connectthe two chambers, thus allowing the fluid entering pressure chamber 4 todischarge into pressure distribution chamber 5 in a uniformlydistributed manner over its length. The pressure distribution chamber isopen at the bottom as a result of a slot 10, which slot is narrowrelative to the diameter of the cavity of pressure distribution chamber5 and also extends the length of the manifold.

Upper section 1 is permanently screwed onto lower section 2 forming afluid-tight seal. The seal is created by the O-ring 11 which is insertedin an annular groove 11′ of upper section 1. At the center betweenO-ring 11, slot 10 surrounds a spring projection 23 which is fitted intoan appropriate groove 25 of lower section 2. Another annular groove 12′is incorporated in the base of base of groove 25 of lower section 2, inwhich groove 12′ O-ring 12 is inserted to seal jet strip 14. In line andbelow fluid passages 9 and slot 10, another slot 13 is incorporated inlower section 2, which slot is extremely narrow at the top, providing anopening which is only slightly wider than the width of the effective jetorifices of jet strip 14.

In alignment with covers 6, 7, or with the back housing end wall 15,lower section 2 is screwed on forming a fluid-tight seal by additionalcovers 16 and 17. One groove 18, 19 each is incorporated in covers 16,17 at the level of lower jet strip 14 retained in the lower section,into which grooves jet strip 14 projects, thereby allowing it to beeasily grasped for removal and replacement after disassembly of covers16 or 17.

In place of the screw-on covers 16, 17 of FIGS. 1, 2, the screws ofwhich are unscrewed and set aside together with covers 16, 17 duringreplacement, a projecting closing unit 26 is provided according to FIGS.4, 5 opposite the front side of upper section 1 of the jet manifold,which unit allows for rapid replacement of jet strip 14. The unit iscomposed of a block matching the width of the jet manifold, one side ofwhich is permanently screwed onto lower section 2 of the jet manifold byscrews 27, 28, and which block includes at the center of this side acontinuous slot 29 to allow insertion of jet strip 14. On the other sideat the same level is an insertion slot which is open to the outside andallows insertion of jet strip 14 and may be closed by insertion mandrel31. In order to secure insertion mandrel 31 in the insertion slot whichis expanded relative to insertion opening 30, closing unit 26 of FIG. 4has a hole 32 running continuously from top to bottom which is matchedby an aligned hole 33 in insertion mandrel 31 when in the inserted statein insertion opening 30. Insertion mandrel 31 is secured to closing unit26, and thus to the jet manifold, by these holes 32, 33 passing throughparts 26 and 31, and by the bolt 34 inserted therein. Bolt 34 is easilymanipulated in its holes 32, 33 by closing unit 26 which projectsopposite the front side of the jet manifold.

Insertion mandrel 31 is sealed by an O-ring 35 in insertion opening 30,while block 26 along with its end 26′ extending into jet manifold 1, 2is sealed by a ring gasket 36 at the front side of end 26′ within uppersection 1 and lower section 2.

In FIG. 4, jet strip 14 is secured in a slot 37 at the end of insertionmandrel 31, for example, by a pin 38 or a friction spring, and mayeasily be moved back and forth by a grip 39 at the other end ofinsertion mandrel 31. To replace the jet strip, it is only necessary toremove the water pressure in the jet manifold and withdraw bolt 34. Jetstrip 14 may then be easily removed by grip 39, and the new stripinserted after replacement of jet strip 14 is completed. To secureinsertion mandrel 31, it is then only necessary to once again insertbolt 34 through holes 32, 33. The water pressure may then be increased.

In the device of FIGS. 6-9 employing the same principle, the rapidreplacement device for jet strip 14 has been modified. This device iscomposed of two spring strips 40, 41 pressed against each other whichare attached one above the other to the front side of insertion mandrel31 and parallel to jet strip 14. Spring strips 40, 41 are bent upward attheir free ends as shown in FIG. 9a. A short pin or a hemisphere 42 isattached in the region of this bend to lower spring strip 40, which pinor hemisphere penetrates a matching hole 43 in the upper spring strip 41when spring strips 40, 41 are in contact with each other. One end of jetstrip 14 has a corresponding hole 44 through which sphere 42 of springstrip 40 passes in order to retain strip 14 on insertion mandrel 31. AsFIG. 9e shows, this arrangement allows jet strip 14 to be quicklyreplaced. The two spring strips 40, 41 are intended to be bent upwardsonly with the end of jet strip 14, and the replacement procedure for thearrangement is intended to be performed according to FIGS. 9g and h.

In the example of FIGS. 6-8, bolt 34′ extends horizontally rather thanvertically. Bolt 34′ thus covers the insertion holes for screws 27, 28;however, these are deeply countersunk and rarely need to be replaced. Inaddition, the free end of bolt 34′ projects from closing unit 26, therepassing through ring 45 which functions as a contact sensor for theproperly locked closing unit 26. In this regard, the ring 45 laterallyattached to closing unit 26 is connected electrically through wires 46to the control unit of the jet manifold in which the water pressure isincreased only when closing unit 26 is properly blocked by bolt 34′.

What is claimed is:
 1. Jet manifold on a device for generating extremelyfine fluid jets used in the hydrodynamic jet impingement of fibers of aweb moving along the manifold, which manifold is composed of an uppersection extending over the working length of the web, and of a lowersection, wherein a) a pressure chamber of round cross-section is locatedalong the length of the upper section, the fluid being supplied underpressure, the chamber; b) a pressure distribution chamber is provided inthe lower section in parallel to the pressure chamber; c) the pressuredistribution chamber discharges into a narrow fluid outlet slit oppositethe cross-section of the pressure distribution chamber; d) a jet stripis mounted in a fluid-tight fashion within the jet manifold above thefluid outlet slit; e) the jet strip may be replaced through a closableinsertion opening on a front side of the jet manifold, characterized inthat f) a closing unit is provided on the closable insertion openingwhich g) is provided at the level of the jet strip mounting positionwith an insertion slot for the jet strip, which slot h) is closable byan insertion mandrel.
 2. Jet manifold according to claim 1,characterized in that the closing unit (26) projects opposite the frontside of the jet manifold (1, 2).
 3. Jet manifold according to claim 1,characterized in that the insertion mandrel (31) is retained on the jetmanifold (1, 2) by a bolt (34, 34′) secured within the closing unit(26).
 4. Jet manifold according to claim 3 characterized in that thebolt (34′) inserted into the closing unit (26) contacts an operatingswitch (45, 46) which enables start-up of the jet manifold after contacthas been made.
 5. Jet manifold according to claim 4, characterized inthat the operating switch (45, 46) is attached to the closing unit (26)on the exit side of the bolt (34′).
 6. Jet manifold according to claim4, characterized in that the operating switch (45, 46) is composed of anelectrically activatable ring (45) which triggers the “on” contact whenthe bolt (34′) is inserted.
 7. Jet manifold according to claim 1,characterized in that the insertion slot (29) in the closing unit (26)is enlarged relative to the dimensions of the jet strip (14) and thatthe insertion mandrel (31) fills the insertion opening (30).
 8. Jetmanifold according to claim 3, characterized in that the closing unit(26) has a passage (32) oriented vertically to the axis of the insertionopening (30), through which passage the bolt (34, 34′) is movable, andthat the insertion mandrel (31) has an alignment hole (33) matched tothe diameter of the bolt (34, 34′).
 9. Jet manifold according to claim1, characterized in that the front side of the insertion mandrel (31) isprovided with a retainer for the jet strip (14).
 10. Jet manifoldaccording to claim 9, characterized in that the jet strip (14) isattached in an easily replaceable manner to the retainer.
 11. Jetmanifold according to claim 9, characterized in that the insertionmandrel (31) has a blind slot (37) on its front side which is matched tothe jet strip (14).
 12. Jet manifold according to claim 11,characterized in that the jet strip (14) is retained in an easilyreplaceable manner within the blind slot (37).
 13. Jet manifoldaccording to claim 9, characterized in that the retainer is composed oftwo spring strips (40, 41) which are pressed together, are attached tothe insertion mandrel (31) and freely project from said mandrel, betweenwhich spring strips the jet strip (14) is retained.
 14. Jet manifoldaccording to claim 13, characterized in that a spherical projection (42)is attached to one of the spring strips (40), which projection extendsinto a hole (43) of the opposing spring strip (41).
 15. Jet manifoldaccording to claim 9, characterized in that the jet strip (14) has ahole (44) at one end which engages the retainer of the closing unit(26).
 16. Jet manifold according to claim 1, characterized in that anO-ring (35) is provided around the circumference of the insertionmandrel (31).
 17. Jet manifold according to claim 9, characterized inthat a grip (39) is provided on the end of the insertion mandrel (31)opposite the retainer of the jet strip (14).
 18. Jet manifold accordingto claim 1, characterized in that the closing unit (26) projectingopposite the front side of the jet manifold (1, 2) is composed of ablock, the lateral ends of which on both sides of the insertion openingare attached by being screwed together (27, 28) to the front side of thejet manifold (1, 2), in the center section of which the insertion slot(29) is provided for the jet strip (14), and this strip is retainedthere.
 19. Jet manifold according to claim 18, characterized in that afree end (26′) of the closing unit (26) extending into the jet manifold(1, 2) along a corresponding groove within the jet manifold is sealed(36) relative to the jet manifold (1, 2).